The present invention relates to a method and a system for assisting the piloting of an aircraft, and to an aircraft equipped with such a system.
During the phases of take-off and landing, and more generally of movement on the ground of the aircraft, knowledge of the surface state of the runway is of capital importance.
Indeed, prediction of braking performance of the aircraft depends on that knowledge. It is thus possible:
to estimate as best possible the distance required to stop the aircraft at the time of its landing, in the interest of safety,
not to overestimate that stopping distance required to immobilize the aircraft and thus not to excessively penalize the operations of use of the runway and of the aircraft.
Numerous assistance systems for piloting require precise knowledge of this runway state.
For example, documents FR2817979 and FR2857468 propose devices for assisting piloting during the approach and landing phases, known under the name Brake-To-Vacate (BTV), making it possible to monitor and control the braking of the aircraft via closed loop control laws. These control laws directly depend on the estimation of stopping distances based on the runway state.
Furthermore, documents FR2936077 and FR2914097 provide devices for assisting piloting during the approach and landing phases, known under the name Runway Overrun Protection (ROP) or Runway Overrun Warning (ROW), enabling detection of an overrun risk on the basis of the runway state, in order to warn the pilot either so as to incite him to perform a go-around, or to apply maximum braking.
However, the braking performance of an aircraft on a contaminated runway and thus the required stopping distance are difficult to predict on account of the difficulty of reliably and precisely knowing the runway state, which is decisive in the deceleration of the aircraft.
Conventionally, the runway state is determined by staff on the ground, or evaluated by a pilot on landing and entered in a landing report. This runway state information, sent to the aircraft in approach phase, is however of low reliability and may become rapidly out of date. To be precise, the runway state characteristics are highly volatile over time.
In order to render more reliable the estimation of a runway state, documents FR2930669 and FR2978736 provide solutions enabling the runway state for landing to be automatically estimated on the basis of measured landing performances of an aircraft on landing, this being independently of the aircraft type.
However, the runway state so determined and provided to the aircraft on approach phase does not enable such a possible runway degradation occurring between the two landings to be shown.
The present invention is directed to improving the assistance for piloting an aircraft in particular during the landing phase to take into account that possible runway degradation.